Two long wires lie in an xy plane, and each carries a current in the positive direction of the $x$ axis. Wire 1 is at $y=10.0 \mathrm{cm}$ and carries 6.00 $\mathrm{A}$ ; wire 2 is at $y=5.00 \mathrm{cm}$ and carries 10.0 $\mathrm{A}$ . (a) In unit-
vector notation, what is the net magnetic field $\vec{B}$ at the origin? (b)
At what value of $y$ does $\vec{B}=0 ?$ (c) If the current in wire 1 is reversed, at what value of $y$ does $\vec{B}=0 ?$